The present invention relates to mechanisms for a scanner and, more particularly, to a vibration inhibiting mechanism for a scanner that limits the movement of a chassis containing an image detecting device in the scanner along a Z direction.
FIG. 1 illustrates a simplified schematic diagram of a conventional scanner, the scanner of this type includes a casing 100 with a glass panel 60 fitted on its top, and a chassis 20 mounted therein. The chassis 20 is slidably coupled with a pair of parallel aligned slide levers 40 disposed in the casing for a driving mechanism (to be described below) to drive the chassis 20 to slidably move along the extending direction (designated with X direction in the drawing) of the slide levers 40. In the chassis 20, an image scanning mechanism (not shown) is mounted for scanning the document positioned over the glass panel 60. The aforementioned image scanning mechanism in general includes a change-coupled device, a set of reflecting mirrors, a light-emitting source, and a signal conversion device. As shown in FIG. 1, the driving mechanism in the chassis 20 consists of a servo motor 70, a pulley 72 driven by the servo motor 70, and a driving belt 74 winding around the pulley 72. Since the driving belt 74 is connected to one side of the chassis 20, the rotation of the pulley 72 driven by the servo motor 70 will drive the driving belt 74 to move to thereby cause the chassis 20 to move along the X direction of the casing 100.
As shown in FIG. 1, the chassis 20 is held in position by the slide levers 40, which confines the chassis 20 to slidably move horizontally with respect to the casing 100, that is, in the X direction, and assures that the chassis 20 will not move vertically with respect to the casing 100, that is, in the Z direction, whereby scanning quality can be maintained. However, because the chassis 20 is made of a metallic material which requires delicate surface treatment, the manufacturing of the slide levers 40 has the drawback of high production cost.
FIG. 2 illustrates a sectional view of another conventional scanner in which the chassis 20 has one side fitted onto a slide lever 40 inside the casing 100 and is driven by a belt 74, while on the other side of the chassis 20 a roller (or a round smooth jut) 22 that can roll (or slides) on the inner surface of the casing 100, is mounted. Though this type of scanner that uses only one slide lever 40 could be lower in production cost than the prior art as aforementioned, one side of the chassis 20 which is adapted to rest on the inner of the casing 100 is not subject to any restriction along the Z direction of the chassis 20. Therefore, vibration of the chassis 20 occurs when the chassis 20 is one sidedly driven by the pulley 74 during the operation of the scanner, or when the inner surface of the casing 100 is not sufficiently smooth, resulting in unsatisfactory scanning quality.
Since the chassis 20 is not restricted in movement along the Z direction, it can be easily damaged or dislocated when the scanner is subjected to a drop test. The aforementioned scanner with a single slide lever 40 thus requires a retainer 104, as shown in FIG. 2, to limit the movement of the chassis 20 along the Z direction. However, the retainer 104 which is mounted to prevent the chassis 20 from being damaged or dislocated during a drop test or transportation must be removed before the scanner is used, so as to prevent vibration of the chassis 20 along the z direction when the scanner is in operation.
It is therefore a primary objective of the present invention to provide a vibration inhibiting mechanism for scanner that can limit the movement of the chassis equipped with an image detecting device in a scanner in order to reduce the production cost and vibration when the chassis is in operation.
Another objective of the invention is to provide a vibration inhibiting mechanism for scanner that can prevent damage or dislocation to the chassis in a scanner during drop test or transportation process without the need of a retainer.
To achieve the above and other objectives, the present invention provides a vibration inhibiting mechanism for scanner having a casing with a glass panel formed on the top side thereof and a chassis movably installed in the casing for allowing an image detecting device coupled to the chassis to scan document positioned on the glass panel, in which the vibration inhibiting mechanism comprises a base mounted in the chassis, a roller support resiliently sleeved in the base toward and being adapted to retractably move toward and away from the glass panel, and a roller rotatably mounted on the roll assembling portion of the roller support and adapted to abut against and roll on the glass panel when the chassis is driven to move.
The roller support can be resiliently supported by a resilient member, for example, a coiled spring or a spring plate, to allow the roller support to retractably move toward and away from the glass panel. By the use of the resilient member, the roller can constantly abut against the glass panel by the upward urging force exerted by the roller support to thereby keep the chassis from vibration during the movement of the chassis.
Furthermore, the base is preferably a round or rectangular cylindrical body. The base can be axially formed with a pair of grooves on the top of the base. When the roller support and the resilient member are accommodated in the base, a pair of corresponding protrusions laterally protruded from the outer wall of the roller support are to be engaged with the grooves so as to prevent the roller support from rotation in relation to the base. In this case, the top of the roller support is formed with a pair of upwardly protruded flanges for coupling with the roller to allow the roller to rotate therebetween. member are accommodated in the base, a pair of corresponding protrusions laterally protruded from the outer wall of the roller support are to be engaged with the grooves so as to prevent the roller support from rotation in relation to the base. In this case, the top of the roller support is formed with a pair of upwardly protruded flanges for coupling with the roller to allow the roller to rotate therebetween.
Furthermore, the base may also be a round recess or a rectangular recess formed on the chassis to respectively accommodate the roller support and the resilient member.